Provided is an intermediate system to intermediate system routing protocol based notification method. The method includes: within a delay period since an intermediate system (IS) establishes a new neighbor, notifying the outside through a link state protocol (LSP) data packet that a METRIC for traffic of the IS reaching the new neighbor is a preset value; after the delay period expires, restoring the METRIC to a normal value, where the preset value is greater than the normal value. Further provided are an intermediate system to intermediate system routing protocol based notification apparatus, a storage medium and a processor.